Robot Mechanic Could Prevent Satellites From Becoming Space Junk

DARPA plans to send a robotic service technician to repair broken satellites in geosynchronous orbit

By Gordon Roesler, Paul Jaffe, Glen Henshaw and Alyssa Pagano

Let’s say you are the program manager of a very large, complex system. Perhaps it’s an aircraft, or a building, or a communications network. Your system is valued at over US $500 million. Could you imagine being told that you won’t ever be able to maintain it? That once it’s operational, it will never be inspected, repaired, or upgraded with new hardware?

Welcome to the world of satellite building. After a satellite is launched, it is on a one-way journey to disrepair and obsolescence, and there is little anyone can do to alter that path. Faults (which are called anomalies in the space business) can only be diagnosed remotely, using data and inferential reasoning. Software fixes and upgrades may be possible, but the nuts and bolts remain untouched. The upshot: Even if a satellite is operating well, it could lose its state-of-the-art status just a few years into a typical 15-year lifetime.

If governments and private companies could actively repair and revitalize their satellites in geosynchronous orbit—and move them to new orbits as needed—they could extend the lifespans of their investments and substantially defer the cost of building and launching replacements.

To that end, the U.S. Defense Advanced Research Projects Agency (DARPA) has sponsored a project to develop a robotic servicing spacecraft that can work on satellites that were never designed to be repaired—which is pretty much all of the ones in orbit today. The ­public-private partnership, called the Robotic Servicing of Geosynchronous Satellites (RSGS) program, builds on a decade of work by DARPA and the U.S. Naval Research Laboratory, as well as the efforts of university researchers and space agencies around the world.

When RSGS launches in the early 2020s, its robot arm could move GEO satellites to new orbits, fix stuck solar panels, and perform other important repairs. Independently, NASA plans to launch, around the same time, a robotic mission called Restore-L; its aim is to refuel and relocate a government-owned satellite now in low Earth orbit.

If successful, these two missions will push the limits of automation and robotic operation in space. They could be the first steps toward space construction projects such as vast solar arrays that can beam energy back to Earth, robots that could mine asteroids and deflect those that pose a danger to Earth, and many other applications that would revolutionize the way we operate beyond the bounds of Earth’s atmosphere.